Inflator with inflation and deflation effects

ABSTRACT

An inflator with inflation and deflation effects. The inflator includes: a cylinder body in which a piston is fitted for compressing the gas in a compression room formed in the cylinder body between the piston and the front end of the cylinder body; a piston rod having an internal gas passage, a front end of the piston rod extending through a rear end of the cylinder body into the cylinder body to connect with the piston, a front end of the gas passage communicating with the compression room; a handle connected with a rear end of the piston rod, a rear end of the gas passage communicating with outer side; a first one-way valve disposed at a front end of the cylinder body and only permitting the gas to one-way flow between the compression room and outer side; a second one-way valve only permitting the gas to one-way flow between outer side, the gas passage and the compression room. Along the longitude of the inflator, the two one-way valves only permit the gas to one-way flow in the same direction.

FIELD OF THE INVENTION

The present invention is related to an inflating device, and more particularly to an inflator with both inflation and deflation effects. The inflator minimizes the possibility of mis-installation when inflating or deflating an object.

BACKGROUND OF THE INVENTION

A conventional inflator is used to inflate an object. However, such inflator cannot exhaust the gas from the object.

U.S. Pat. No. 6,250,343 of this applicant discloses an inflator which can inflate an object as well as suck gas out of the object.

FIG. 1 shows the structure of the above Patent, in which a piston 12 is disposed in a cylinder body 10. Via a piston rod 14, the piston 12 can be pushed to compress the gas in the internal space 15 of the cylinder body. An intake one-way valve 16 and an exhaust one-way valve 18 are arranged at front end of the cylinder body 10. The intake one-way valve 16 only permits the gas to flow from outer side into the space 15, while the exhaust one-way valve 18 only permits the gas to be exhausted from the space 14 to outer side.

When inflated, a conducting member 19 is mounted at the exhaust one-way valve 18 as shown in FIG. 1. When the piston 12 is pushed toward the front end of the cylinder body 10, the gas in the space 15 is compressed to flow through the exhaust one-way valve 18 and the conducting member 19 into an object to inflate the same. When the piston is pushed in reverse direction, the ambient atmosphere can flow through the intake one-way valve 16 into the space 14.

When deflating the object, the conducting member 19 is mounted at the intake one-way valve 16 as shown in FIG. 2. When the piston 12 is pushed toward the rear end of the cylinder body 10, the gas in the space 15 is decompressed and the gas in the object flows through the conducting member 19 and the intake one-way valve 16 into space 15. Then the piston is pushed toward the front end of the cylinder body so as to exhaust the gas in the space 15 through the exhaust one-way valve 18 to outer side.

According to the above structure, the inflator has both inflation and deflation functions. However, the intake one-way valve 16 and the exhaust one-way valve 18 are both disposed at front end of the cylinder body 10. It is uneasy for a user to distinguish these two one-way valves 16, 18 from each other. As a result, it often takes place that a user mis-mounts the conducting member at an incorrect one-way valve.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide an inflator with both inflation and deflation effects. In inflation or deflation operations, the gas flow ways of the inflator are respectively positioned in the cylinder body and the handle of the inflator. Therefore, a user can easily distinguish the two gas flow ways from each other so as to minimize the possibility of mis-installation.

The present invention can be best understood through the following description and accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 and FIG. 2 are longitudinally sectional views of a prior inflator in operation;

FIG. 3 is a rear perspective view of a preferred embodiment of the present invention, also showing various gas-conducting members co-used with the present invention;

FIG. 4 is a longitudinally sectional view of FIG. 3;

FIGS. 5 and 6 are sectional views according to FIG. 4, showing the inflation operation of the present invention;

FIGS. 7 and 8 are sectional views according to FIG. 4, showing the deflation operation of the present invention;

FIG. 9 is a longitudinally sectional view of another embodiment of the present invention;

FIG. 10 is a longitudinally sectional view of still another embodiment of the present invention;

FIG. 11 is a partial enlarged view of another embodiment according to FIG. 10;

FIG. 12 is a longitudinally sectional view of still another embodiment of the present invention;

FIG. 13 shows the inflation operation according to FIG. 12;

FIG. 14 shows the deflation operation according to FIG. 12;

FIG. 15 is a longitudinally sectional view of still another embodiment of the present invention; and

FIG. 16 is a longitudinally sectional view of still another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 3 and 4. According to a first embodiment, the inflator 20 of the present invention includes a hollow cylinder body 30 and a piston 40. A rear end of the cylinder body 30 is sealed by a rear cap 32. A leakproof member such as an O-ring 42 is fitted around the circumference of the piston 40. The piston 40 is fitted in the cylinder body 30 with the O-ring 42 airtight engaged with inner wall face of the cylinder body. The piston divides the interior of the cylinder body into two spaces. The space between front end of the cylinder body and the piston forms a compression room 34.

A hollow piston rod 50 has an internal gas passage 52. A front end of the piston rod extends through the rear cap 32 into the cylinder body to connect with the piston 40 for driving the piston. A rear end of the piston rod 50 is positioned on outer side of the cylinder body. The front end of the gas passage 52 communicates with the compression room 34.

A handle 55 fixedly connected with the rear end of the piston rod 50 for a user to hold. The mounting structure between the handle and the piston rod will not affect the communication between the rear end of the gas passage 52 and outer side.

A gas passage connector 56 disposed at circumference of the handle and communicating with the rear end of the gas passage 52. In this embodiment, the gas passage connector 56 is directly disposed in the rear end of the piston rod 50 which extends through the handle to the rear end face thereof. Alternatively, as shown in FIG. 10, the gas passage connector 132 can be disposed in the handle 126 and adjacent to the circumference of the handle.

A first one-way valve which is an exhaust one-way valve 60. The one-way valve only permits the gas to flow in one direction. The structure of the one-way valve is not limited to any specific structure. In this embodiment, the one-way valve 60 has a conic flow way 62 and a ball body 64 rollable within the flow way 62. The one-way valve 60 is disposed at front end of the cylinder body 30, permitting the gas to only flow from the compression room 34 of the cylinder body to outer side.

A cylinder body connector 66 disposed at the front end of the cylinder body 30 to communicate with front end of the one-way valve 60.

A second one-way valve which is an intake one-way valve 70. The one-way valve only permits the gas to flow in one direction. The structure of the one-way valve is not limited to any specific structure. The one-way valve 70 is disposed on front end face of the piston 40. A rear end of the one-way valve 70 communicates with the front end of the gas passage 52. The one-way valve 70 permits the gas to only flow from the gas passage 52 into the compression room 34.

The inflator 20 is co-usable with various gas-conducting members as shown in FIG. 3. The gas-conducting member 80 is a metal-made inflating pin and may co-used with a rubber conduit 82. The gas-conducting member 84 is a plastic-made inflating pin.

When inflating an object, a gas-conducting member such as the inflating pin 80 is mounted on the cylinder body connector 66 as shown in FIG. 5. When a user holds the handle 55 to push the piston 40 forward, the gas in the compression room 34 is compressed to flow through the exhaust one-way valve 60 and the gas-conducting member 80 into the inflated object. At this time, the ball body 74 of the intake one-way valve 70 blocks the flow way 72 to prevent the compressed gas from flowing from the compression room into the gas passage 52.

After the forward travel of the piston 40 ends, the piston is pulled backward as shown in FIG. 6. At this time, the capacity of the compression room 34 is enlarged and the pressure of the gas is lowered. The ambient atmosphere goes through the gas passage 52 of the piston rod 50 and the intake one-way valve 70 into the compression room. Therefore, the gas pressure in the compression room is kept equal to the pressure of the atmosphere. The ball body 64 of the exhaust one-way valve 60 blocks the flow way 62 so that the ambient atmosphere cannot flow into the compression room.

After the backward travel of the piston ends, the user can again push the piston to compress the gas in the compression room. By means of repeated operation, the gas is filled into the object.

When deflating the object, the gas-conducting member 80 is mounted at the gas passage connector 56 as shown in FIG. 7. The gas-conducting member is extended into the object. At this time, the cylinder body is pushed and pulled to deflate the object.

When the cylinder body 30 is pulled in a direction away from the handle 55, the gas pressure in the compression room 34 is lowered and thus the gas in the object is sucked into the inflator. The gas flows through the gas passage 52 and the intake one-way valve 70 into the compression room. The pressure of the atmosphere is greater than the gas pressure of the compression room. Therefore, at this time, the exhaust one-way valve 60 is blocked to prevent the ambient gas from flowing into the compression room.

Then the cylinder body 30 is pushed toward the handle 55 as shown in FIG. 8. The compressed gas in the compression room 34 is exhausted through the exhaust one-way valve 60 to outer side. The ball body 74 of the intake one-way valve 70 at this time blocks the flow way 72 to prevent the compressed gas from flowing into the gas passage 52.

By means of repeatedly pushing the cylinder body, the object is deflated.

FIG. 9 shows another embodiment of the present invention, which has a structure substantially identical to the structure of the above embodiment. In this embodiment, the two one-way valves are switched. As shown in FIG. 9, the exhaust one-way valve 92 is disposed on front end face of the piston 94 to communicate with inner end of the gas passage 96 and only permit the gas to flow from the compression room 98 to the gas passage 96. The intake one-way valve 102 is disposed on front end face of the cylinder body 100, only permitting the gas to flow from outer side into the compression room 98.

When inflating an object, a gas-conducting member is mounted on the gas passage connector 104 to communicate with the gas passage. When the gas in the compression room 98 is compressed, the compressed gas flows through the exhaust one-way valve 92, the gas passage 96 and the gas-conducting member into the object. When the capacity of the compression room is enlarged, the ambient atmosphere goes through the intake one-way valve 102 into the compression room.

When deflating the object, the gas-conducting member is mounted at the cylinder body connector 106 to communicate with the intake one-way valve 102. When operating the inflator, the gas in the object will be sucked into the compression room 98 and then exhausted through the gas passage 96 to outer side.

FIG. 10 shows still another embodiment of the inflator 110 of the present invention, in which the first one-way valve 122 such as the exhaust one-way valve/intake one-way valve is disposed at front end of the cylinder body 120 to communicate with the compression room 124. The second one-way valve 125 such as intake one-way valve/exhaust one-way valve is disposed in the gas passage or the handle for controlling the gas to one-way flow within the gas passage.

In FIG. 10, the second one-way valve 125 is disposed in a hole 128 of the handle 126. The piston rod 130 extends into the hole 128 and the gas passage connector 132 is disposed in the hole 128. The one-way valve 125 is positioned between the gas passage connector and the rear end of the piston rod to communicate with the gas passage 134.

Alternatively, the second one-way valve 125′ can be disposed in the piston rod 130′ at outer end of the gas passage 134′ as shown in FIG. 11.

In use, according to the usage, the gas-conducting member is mounted at the cylinder body connector 136 or the gas passage connector 132. When the gas in the compression room 124 is compressed by the piston 138, the gas is exhausted from one of the one-way valves 122 or 125. When the pressure of the gas in the compression room is lowered, the compression room is complemented with the atmosphere through the other one-way valve 125 or 122. Accordingly, the inflation or deflation function can be achieved.

In addition, it should be noted that in FIG. 11, the one-way valve 125′ disposed in the gas passage 134′ can be positioned in any position within the gas passage, for example, the front end, rear end or middle of the gas passage. All can achieve the purpose of one-way flowing of the gas.

FIG. 12 is a sectional view of still another embodiment of the inflator 140 of the present invention, which has a telescopic structure. The inflator 140 includes a main cylinder body 150, a subsidiary cylinder body 155 and a main piston 156 disposed at front end of the subsidiary cylinder body 155. The subsidiary cylinder body 155 extends through the rear cap 152 of the main cylinder body 150 into the main cylinder body 150. The main piston 156 is tightly fitted in the main cylinder body for compressing the gas in the main compression room 154 of the main cylinder body.

A piston rod 160 has an internal gas passage 162. A subsidiary piston 165 is disposed at front end of the piston rod 160. The front end of the piston rod 160 extends through the rear cap 157 of the subsidiary cylinder body into the subsidiary cylinder body 155. The subsidiary piston 165 is tightly fitted in the subsidiary cylinder body for compressing the gas in the subsidiary compression room 158 of the subsidiary cylinder body.

A handle 170 is fixedly connected with rear end of the piston rod 160.

A first one-way valve 180 is disposed at front end of the main cylinder body 150 for communicating the compression room with outer side. The first one-way valve 180 only permits the gas to one-way flow between the outer side and the compression room.

This embodiment further includes two second one-way valves 190, 195. One of the second one-way valves 190 is disposed in the main piston 156 to communicate the subsidiary compression room 158 of the subsidiary cylinder body 155 with the main compression room 154 of the main cylinder body 150, and only permits the gas to one-way flow between the two compression rooms. The other of the two second one-way valves 195 is disposed in the subsidiary piston 165 for communicating the subsidiary compression room 158 and the gas passage 162, and only permits the gas to one-way flow between the subsidiary compression room and the gas passage. The gas one-way flows through the two second one-way valves 190, 195 in the same direction.

The first one-way valve can be an exhaust one-way valve/intake one-way valve. The two second one-way valves can be intake one-way valve/exhaust one-way valves. In FIG. 13, the first one-way valve 180 is the exhaust one-way valve which only permits the gas of the main compression room 154 to one-way flow from the main compression room to outer side. The second one-way valves 190, 195 are the intake one-way valves. The second one-way valve 190 only permits the gas to flow from the subsidiary compression room 158 to the main compression room 154. The other second one-way valve 195 only permits the gas to flow from the gas passage 162 to the subsidiary compression room 158.

When inflating an object, a gas-conducting member 200 is mounted on the cylinder body connector 202. When pushing the handle 170 forward, the gas in the subsidiary compression room 158 is compressed by the subsidiary piston 165. The gas flows through the first intake valve 190 into the main compression room 154. The gas in the main compression room is compressed by the main piston 156 to flow through the exhaust one-way valve 180 into the object.

When the handle 170 is pulled backward, the air pressure in the two compression rooms will be less than the pressure of the atmosphere. Therefore, the atmosphere will flow through the gas passage 162 and the second intake valve 195 into the subsidiary compression room 158 and then flow through the first intake valve 190 into the main compression room 154. Accordingly, the pressure of the gas in the two compression rooms will be equal to the pressure of the atmosphere. The exhaust one-way valve 180 serves to prevent the gas in the object from flowing back into the main compression room 154.

When deflating the object, as shown in FIG. 14, the gas-conducting member 200 is connected with the gas passage connector 204. The main cylinder body 150 is pulled in a direction away from the handle 170. At this time, the air pressure in the compression rooms 154, 158 is lowered so that the gas in the object is sucked through the gas passage 162, the two intake one-way valves 190, 195 into the two compression rooms. Then the main cylinder body 150 is pushed toward the handle 170 to compress the gas in the compression rooms. The gas is then exhausted through the exhaust one-way valve 180 to outer side.

In practice, the first one-way valve 180 can be an intake one-way valve and the two second one-way valves 190, 195 are two exhaust one-way valves. Accordingly, the inflator can still achieve both the inflation and deflation functions.

FIG. 15 shows still another embodiment of the inflator 210 of the present invention, which also is a telescopic structure. The inflator 210 only includes a first one-way valve 222 and a second one-way valve 224. The first one-way valve 222 is disposed at front end of the cylinder body 220 to communicate with the main compression room 226. The second one-way valve 224 is disposed in the subsidiary piston 228 to communicate with the gas passage 230 and the subsidiary compression room 232. The main piston 234 is formed with a through hole 236 for communicating with the main compression room 226 and the subsidiary compression room 232.

The first one-way valve 222 can be an exhaust/intake one-way valve. The second one-way valve 224 can be an intake/exhaust one-way valve. Such inflator can also achieve inflation and deflation effects. In this embodiment, in the case that no one-way valve is disposed in the main piston 234, the function of the inflator will not be affected. This embodiment can achieve the same effect as the embodiment of FIG. 12.

FIG. 16 shows still another embodiment of the present invention, in which the second one-way valve 224′ of FIG. 15 can be positioned in the gas passage 230′ in any position or disposed in the handle 238. It is only required that the second one-way valve controls the gas to one-way flow within the gas passage. The front end of the gas passage 230′ communicates with the subsidiary compression room 232′.

According to the arrangement of the one-way valves of the present invention, when inflating or deflating an object, the gas-conducting member is mounted at front end of the cylinder body or the handle. Therefore, the possibility of mis-installation of the gas-conducting member is minimized.

Besides, the one-way valve design of the present invention only permits the gas to longitudinally flow in the same direction. With the embodiment of FIG. 4 exemplified, a first gas flow way is formed between the outer side of the front end of the cylinder body and the compression room 34. A second gas flow way is formed between the compression room 34, gas passage 52 and outer side. In the first gas flow way, the one-way valve 60 permits the gas to flow from rear side to front side (from compression room to outer side). In the second gas flow way, the one-way valve 70 also permits the gas to flow from rear side to front side (from outer side to the gas passage and then to the compression room). In the two gas flow ways, the gas one-way flows in the same direction. Similarly, in the structure of FIG. 9, the one-way valve 102 permits the gas to flow from front side to rear side (from outer side to the compression room). The one-way valve 92 also permits the gas to flow from front side to rear side (from compression room to the gas passage and then to outer side). In the two gas flow ways, the gas also one-way flows in the same direction.

The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. 

1. An inflator with inflation and deflation effects, comprising: a cylinder body; a piston fitted in the cylinder body and airtight engaged with inner wall of the cylinder body, a compression room being formed in the cylinder body between the piston and a front end of the cylinder body; a piston rod having an internal gas passage, a front end of the piston rod extending through a rear end of the cylinder body into the cylinder body to connect with the piston for driving the piston, a front end of the gas passage communicating with the compression room; a handle connected with a rear end of the piston rod for a user to hold, a rear end of the gas passage keeping communicating with outer side; an exhaust one-way valve disposed at front end of the cylinder body, the exhaust one-way valve only permitting the gas in the compression room to flow from the compression room to outer side; an intake one-way valve positioned in a certain position, the intake one-way valve only permitting ambient atmosphere to one-way flow through the gas passage into the compression room; a gas passage connector located at circumference of the handle to communicate with a rear end of the gas passage; and a cylinder body connector disposed at the front end of the cylinder body to communicate with a front end of the exhaust one-way valve.
 2. The inflator as claimed in claim 1, wherein the intake one-way valve is disposed in the piston to communicate the compression room with the front end of the gas passage.
 3. The inflator as claimed in claim 1, wherein the intake one-way valve is disposed in the gas passage.
 4. The inflator as claimed in claim 1, wherein the intake one-way valve is disposed in the handle between a rear end of the piston rod and the gas passage connector.
 5. The inflator as claimed in claim 1, wherein the gas passage connector is disposed in the handle and exposed at the circumference of the handle.
 6. The inflator as claimed in claim 1, wherein a rear end of the piston rod extends to a rear end of the handle and the gas passage connector is disposed in the rear end of the piston rod.
 7. An inflator with inflation and deflation effects, comprising: a cylinder body; a piston fitted in the cylinder body and airtight engaged with inner wall face of the cylinder body, a compression room being formed in the cylinder body between the piston and a front end of the cylinder body; a piston rod having an internal gas passage, a front end of the piston rod extending through a rear end of the cylinder body into the cylinder body to connect with the piston for driving the piston, a front end of the gas passage communicating with the compression room; a handle connected with a rear end of the piston rod for a user to hold, a rear end of the gas passage keeping communicating with outer side; an intake one-way valve disposed at front end of the cylinder body, only permitting the gas to flow from outer side into the compression room; an exhaust one-way valve positioned in a certain position, the exhaust one-way valve only permitting the gas in the compression room to flow from the compression room into the gas passage and then flow from the rear end of the gas passage to outer side; a gas passage connector located at circumference of the handle to communicate with a rear end of the gas passage; and a cylinder body connector disposed at the front end of the cylinder body to communicate with a front end of the intake one-way valve.
 8. The inflator as claimed in claim 7, wherein the exhaust one-way valve is disposed in the piston to communicate the compression room with the front end of the gas passage.
 9. The inflator as claimed in claim 7, wherein the exhaust one-way valve is disposed in the gas passage.
 10. The inflator as claimed in claim 7, wherein the exhaust one-way valve is disposed in the handle between a rear end of the piston rod and the gas passage connector.
 11. An inflator with inflation and deflation effects, comprising: a main cylinder body; a subsidiary cylinder body; a main piston disposed at a front end of the subsidiary cylinder body, the subsidiary cylinder body extending through rear end of the main cylinder body into the main cylinder body, the main piston being airtight fitted in the main cylinder body, a main compression room being formed in the main cylinder body between front end of the main cylinder body and the main piston; a subsidiary piston airtight fitted in the subsidiary cylinder body, a subsidiary compression room being formed in the subsidiary cylinder body between front end of the subsidiary cylinder body and the subsidiary piston, the subsidiary compression room communicating with the main compression room; a piston rod having an internal gas passage, a front end of the piston rod extending through rear end of the subsidiary cylinder body into the subsidiary cylinder body to connect with the subsidiary piston, a front end of the gas passage communicating with the subsidiary compression room; a handle connected with a rear end of the piston rod, a rear end of the gas passage keeping communicating with outer side; an exhaust one-way valve disposed at front end of the cylinder body, only permitting the gas to flow from the main compression room to outer side; a first intake one-way valve disposed in a certain position, the first intake one-way valve only permitting the ambient atmosphere to one-way flow through the gas passage into the subsidiary compression room; a gas passage connector located at circumference of the handle to communicate with a rear end of the gas passage; and a cylinder body connector disposed at the front end of the cylinder body to communicate with a front end of the exhaust one-way valve.
 12. The inflator as claimed in claim 11, wherein the intake one-way valve is disposed in the subsidiary piston.
 13. The inflator as claimed in claim 11, wherein the intake one-way valve is disposed in the gas passage.
 14. The inflator as claimed in claim 11, wherein the intake one-way valve is disposed in the handle between a rear end of the piston rod and the gas passage connector.
 15. The inflator as claimed in claim 11, further comprising a second intake one-way valve disposed in the main piston, the second intake one-way valve only permitting the gas to flow from the subsidiary compression room to the main compression room.
 16. An inflator with inflation and deflation effects, comprising: a main cylinder body; a subsidiary cylinder body; a main piston disposed at a front end of the subsidiary cylinder body, the subsidiary cylinder body extending through rear end of the main cylinder body into the main cylinder body, the main piston being airtight fitted in the main cylinder body, a main compression room being formed in the main cylinder body between front end of the main cylinder body and the main piston, the main piston being formed with a through hole communicating with an interior of the subsidiary cylinder body; a subsidiary piston airtight fitted in the subsidiary cylinder body, a subsidiary compression room being formed in the subsidiary cylinder body between front end of the subsidiary cylinder body and the subsidiary piston, the through hole communicating the subsidiary compression room with the main compression room; a piston rod having an internal gas passage, a front end of the piston rod extending through rear end of the subsidiary cylinder body into the subsidiary cylinder body to connect with the subsidiary piston, a front end of the gas passage communicating with the subsidiary compression room; a handle connected with rear end of the piston rod, a rear end of the gas passage keeping communicating with outer side; an intake one-way valve disposed at a front end of the cylinder body and only permitting the gas to flow from outer side into the compression room; a first exhaust one-way valve disposed in a certain position, the first exhaust one-way valve only permitting the gas to one-way flow from the subsidiary compression room into the gas passage and then flow from outer end of the gas passage to outer side; a gas-passage connector located at circumference of the handle to communicate with a rear end of the gas passage; and a cylinder body connector disposed at the front end of the cylinder body to communicate with a front end of the exhaust one-way valve.
 17. The inflator as claimed in claim 16, wherein the exhaust one-way valve is disposed in the subsidiary piston.
 18. The inflator as claimed in claim 16, wherein the exhaust one-way valve is disposed in the gas passage.
 19. The inflator as claimed in claim 16, wherein the exhaust one-way valve is disposed in the handle between a rear end of the piston rod and the gas passage connector.
 20. The inflator as claimed in claim 16, further comprising a second exhaust one-way valve disposed in the main piston, the second exhaust one-way valve only permitting the gas to flow from the main compression room to the subsidiary compression room.
 21. An inflator with inflation and deflation effects, comprising: a cylinder body; a piston fitted in the cylinder body, a compression room being formed in the cylinder body between the piston and a front end of the cylinder body; a piston rod having an internal gas passage, a front end of the piston rod extending through a rear end of the cylinder body into the cylinder body to connect with the piston for driving the piston, a front end of the gas passage communicating with the compression room; a handle connected with a rear end of the piston rod for a user to hold, a rear end of the gas passage keeping communicating with outer side; a first one-way valve disposed at a front end of the cylinder body, the first one-way valve only permitting the gas to one-way flow between outer side and the compression room, a first gas flow way being formed between the compression room and outer side; a second one-way valve positioned in a certain position, a second gas flow way being formed between outer side, the gas passage and the compression room, the second one-way valve only permitting the gas to one-way flow within the second gas flow way, along the longitude of the inflator, the two one-way valves only permitting the gas to one-way flow within the two gas flow ways in the same direction; a gas passage connector located at circumference of the handle to communicate with a rear end of the gas passage; and a cylinder body connector disposed at the front end of the cylinder body to communicate with a front end of the exhaust one-way valve. 